Synapse

Synapse is the "New Continent" that Sugata had been searching for and found out that it's connected to Tomoki's dream. The only way for them to enter Synapse is through the Dive Game. In his findings, Sugata finds that some people on earth are not "real", but in fact are just angels dreaming and that it is where the Angeloids had been developed.

The Synapse first appears as a grassy field through Tomoki's dreams. However, later when Sugata keeps re-entering, it's revealed Synapse is divided into separate "islands", some islands are organic while others are not.

Tomoki, Sohara, Sugata, and Mikako visited an island with a single large structure that had writings on it (as seen on the picture). It is rumored that these are the rules that all residents of Synapse must follow, however, there aren't enough details to confirm this.